全文获取类型
收费全文 | 388篇 |
免费 | 28篇 |
出版年
2023年 | 8篇 |
2022年 | 2篇 |
2021年 | 25篇 |
2020年 | 16篇 |
2019年 | 11篇 |
2018年 | 19篇 |
2017年 | 13篇 |
2016年 | 24篇 |
2015年 | 26篇 |
2014年 | 28篇 |
2013年 | 37篇 |
2012年 | 33篇 |
2011年 | 47篇 |
2010年 | 13篇 |
2009年 | 17篇 |
2008年 | 17篇 |
2007年 | 20篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 14篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
排序方式: 共有416条查询结果,搜索用时 328 毫秒
401.
402.
Effect of humanin analogues on experimentally induced impairment of spatial memory in rats. 总被引:2,自引:0,他引:2
Humanin and its analogues have been shown to protect cells against death induced by various Alzheimer's disease genes and amyloid-beta-peptides in vitro: the analogue [Gly14]-humanin has also been shown to be potent in reversing learning and memory impairment induced by scopolamine in mice in vivo. It is important to validate these results by using other behavioral methods. In this study, the effect of [Gly14]-humanin and des-Leu-PAGA, another analogue (0.2 micromol kg(-1), i.p.) on the 3-quinuclidinyl benzilate-induced (2 mg kg(-1), i.p.) impairment of spatial memory in the multiple T-maze in rats has been evaluated. Both peptides reversed the impairment of spatial memory. These results indicate the potential of humanin analogues in modulation of the cholinergic system. 相似文献
403.
404.
Jan Vondrk Ivan Frolov Jií Konar Ulf Arup Tereza Veselsk Gkhan Halc Jií Malí
ek Ulrik Schting 《植物分类学报:英文版》2020,58(3):295-330
Blastenia is a widely distributed lichen genus in Teloschistaceae. We reconstructed its phylogeny in order to test species delimitation and to find evolutionary drivers forming recent Blastenia diversity. The origin of Blastenia is dated to the early Tertiary period, but later diversification events are distinctly younger. We recognized 24 species (plus 2 subspecies) within 6 infrageneric groups. Each species strongly prefers a single type of substrate (17 species occur on organic substrates, 7 on siliceous rock), and most infrageneric groups also show a clear substrate preference. All infrageneric groups tend to have the Mediterranean and Macaronesian distribution, but some epiphytic species have much larger geographic ranges and some evolved after a long‐distance dispersal outside the region. Chlorinated and nonchlorinated anthraquinone chemosyndromes co‐occur in apothecia of most species, but the chemotype has been secondarily reduced in some lineages. One infrageneric group has a marked reduction in apothecial size, associated with a substrate shift to twigs. Only seven species have vegetative diaspores; they also produce apothecia but have smaller ascospores. Genome sizes (22‐35 Mb in Blastenia) are significantly higher in epilithic species. Within‐species genetic variation is low in widely distributed species but high in some epilithic species with small geographical ranges. New taxa are: B. afroalpina, B. anatolica, B. caucasica, B. gennargentuae, B. herbidella subsp. acidophila, B. lauri, B. monticola, B. palmae, B. psychrophila, B. purpurea, B. relicta, B. remota, B. xerothermica, and B. xerothermica subsp. macaronesica. New combinations are: B. festivella and B. subathallina; both names and B. catalinae are lectotypified. 相似文献
405.
Mariana Laís Boaretto Brbara Zanardini de Andrade Jhyslayne Igncia Hoff Nunes Maciel Mylena de Campos Oliveira Camila Maria Toigo de Oliveira Ana Tereza Bittencourt Guimares Mrcia Miranda Torrejais Sara Cristina Sagae Schneider Lucinia de Ftima Chasko Ribeiro Gladson Ricardo Flor Bertolini 《Journal of musculoskeletal & neuronal interactions》2020,20(4):570
Objectives:evaluate the effects that whole-body vibration (WBV) causes on the neuromuscular junctions and oxidative stress of the soleus muscle of obese Wistar rats.Methods:32 male Wistar rats were used, 16 of which were obesity induced by monosodium glutamate, randomized into four groups: control (GC), control with WBV (GCP), obese (GO) and obese with WBV (GOP). At the 70 days old, the training on WBV was started, performed 3 times a week, during 8 consecutive weeks. At the 130 days old, the animals were euthanized and the soleus muscles were collected.Results:Regarding the analysis of the neuromuscular junctions, the obese groups had lower mean size when compared to the control groups. On the other hand, the WBV presented higher averages when compared to the groups that did not perform the training. Regarding the oxidative stress, for the lipid peroxidation there was a significant difference between obese and non-obese animals, however, there was no difference between the animals WBV and those who did not.Conclusion:WBV promotes beneficial changes such as increased measurements of the structures of the neuromuscular junctions, but is not able to promote changes in the concentration of the cholinesterase enzyme in the synaptic cleft. 相似文献
406.
Mateusz Baca Danijela Popović Anna Lemanik Sandra Bañuls-Cardona Nicholas J. Conard Gloria Cuenca-Bescós Emmanuel Desclaux Helen Fewlass Jesus T. Garcia Tereza Hadravova Gerald Heckel Ivan Horáček Monika Vlasta Knul Loïc Lebreton Juan Manuel López-García Elisa Luzi Zoran Marković Jadranka Mauch Lenardić Xabier Murelaga Pierre Noiret Alexandru Petculescu Vasil Popov Sara E. Rhodes Bogdan Ridush Aurélien Royer John R. Stewart Joanna Stojak Sahra Talamo Xuejing Wang Jan M. Wójcik Adam Nadachowski 《Journal of Biogeography》2023,50(1):183-196
407.
408.
Guillermo M. Zúiga-Gonzlez Cecilia M. Batista-Gonzlez Belinda C. Gmez-Meda María L. Ramos-Ibarra Ana L. Zamora-Perez Tereza Muoz-Magallanes Carmen Ramos-Valds Martha P. Gallegos-Arreola 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2007,634(1-2):126-134
Diabetes mellitus (DM) is associated with a high risk of health complications, mainly due to excessive free radical (FRs) production that could result in an increased frequency of micronuclei. The consumption of antioxidants, like folic acid (FA), may mitigate the effects of the FRs. In the present study, micronucleated polychromatic erythrocyte (MNPCE) frequencies were determined in blood sampled weekly from the tails of pregnant female Wistar rats and pregnant Wistar rats with experimental diabetes that were given unsupplemented diets and diets supplemented with FA. At birth, the pups were sampled to analyze micronucleated erythrocyte (MNE) and MNPCE frequencies. Moreover micronucleated cells (MNCs) were evaluated in buccal mucosa samples taken from 81 healthy adult subjects, 48 patients with DM, and 30 DM patients who were sampled before and after FA treatment. Increases in MNPCE frequencies were significant only at the first sampling (P < 0.01 and P < 0.03) in pregnant rats with experimental diabetes. In addition, the pups from the diabetic group and from diabetic group treated with FA had higher frequencies of MNEs (P < 0.03 and P < 0.001, respectively) and MNPCEs (P < 0.009 and P < 0.05, respectively) than the controls. No differences were found in diabetic rats and newborn rats born to diabetic mothers treated with FA compared with untreated animals. Patients with DM had a higher frequency of MNCs compared with healthy subjects (P < 0.001). Also FA reduced the frequency of MNCs in DM patients (P < 0.001). The results of this study indicate that diabetes results in elevated frequencies of micronuclei, and that, at least in humans, FA can protect against the elevation. 相似文献
409.
A model of dopamine and serotonin-kynurenine metabolism in cortisolemia: Implications for depression
Felipe Dalvi-Garcia Luis L. Fonseca Ana Tereza R. Vasconcelos Cecilia Hedin-Pereira Eberhard O. Voit 《PLoS computational biology》2021,17(5)
A major factor contributing to the etiology of depression is a neurochemical imbalance of the dopaminergic and serotonergic systems, which is caused by persistently high levels of circulating stress hormones. Here, a computational model is proposed to investigate the interplay between dopaminergic and serotonergic-kynurenine metabolism under cortisolemia and its consequences for the onset of depression. The model was formulated as a set of nonlinear ordinary differential equations represented with power-law functions. Parameter values were obtained from experimental data reported in the literature, biological databases, and other general information, and subsequently fine-tuned through optimization. Model simulations predict that changes in the kynurenine pathway, caused by elevated levels of cortisol, can increase the risk of neurotoxicity and lead to increased levels of 3,4-dihydroxyphenylaceltahyde (DOPAL) and 5-hydroxyindoleacetaldehyde (5-HIAL). These aldehydes contribute to alpha-synuclein aggregation and may cause mitochondrial fragmentation. Further model analysis demonstrated that the inhibition of both serotonin transport and kynurenine-3-monooxygenase decreased the levels of DOPAL and 5-HIAL and the neurotoxic risk often associated with depression. The mathematical model was also able to predict a novel role of the dopamine and serotonin metabolites DOPAL and 5-HIAL in the ethiology of depression, which is facilitated through increased cortisol levels. Finally, the model analysis suggests treatment with a combination of inhibitors of serotonin transport and kynurenine-3-monooxygenase as a potentially effective pharmacological strategy to revert the slow-down in monoamine neurotransmission that is often triggered by inflammation. 相似文献
410.